1. Technical Field
The present disclosure relates to an optical sheet and a light emitting apparatus including a light scattering layer that scatters at least a part of light incident on the light scattering layer by diffraction.
2. Description of the Related Art
In general, when light tries to propagate from a medium having a high refractive index to a medium having a low refractive index, total reflection of the light occurs when the incident angle of the light is greater than a critical angle. Therefore, in a light emitting apparatus, such as an organic electroluminescence apparatus, there may be a problem that light is totally reflected by an interface between stacked materials and confined in the light emitting apparatus as a result. Accordingly, light emitting apparatuses including an optical sheet for extracting light incident on the optical sheet at an incident angle greater than the critical angle to the outside has been proposed.
For example, Japanese Patent No. 4346680 (hereinafter referred to as Patent Document 1) discloses an optical sheet in which small projections and recesses are randomly arranged. When this optical sheet is assembled in a light emitting apparatus, at least a part of light incident on the optical sheet at an incident angle greater than a critical angle can be scattered as a result of the phenomenon of light diffraction, and thereby extracted to the outside.